Conventional cathode ray tube (CRT) image display apparatuses are rapidly being replaced with liquid crystal, plasma, and other flat-panel displays. In the early days when liquid-crystal displays were first developed, their motion display performance, which was greatly inferior to that of CRTs, was regarded as problematic. This problem was due to the slow response speed of the liquid crystal, and more generally to the effect of motion blurring caused by any display of the hold type.
With technological progress in recent years, the problem of slow liquid crystal response has been largely overcome by improvements in liquid crystal materials and the development of over-drive technology. In relation to the problems caused by use of a hold-type display, a method of displaying black images between frames to be displayed and a method of generating new sub-frames by employing image interpolation techniques have been proposed. As the motion display performance of flat-panel displays is being improved in this way, a need has arisen to deal with motion blur included in the video images received by the improved display apparatus.
Image signals received by display apparatuses are obtained by quantizing the total amount of light received by the photodetector of a camera from a subject during a frame integration time ( 1/60 second, for example) and are arranged in a standardized pixel sequence. When there is relative motion between the photodetector of the camera and the subject, edges of the subject may be blurred (referred to as motion blur below) depending on the frame integration time and the relative speed of the camera and the subject.
As a method of reducing blur in images, a method employing a zooming circuit has been disclosed, as in Patent Document 1, for example. This method is expected to be effective for isotropic narrow-width blur caused by out-of-focus conditions at the time of image capture or other such problems, because it can sharpen the rise and fall of edges in an image by using filtering techniques without adding overshoot or undershoot. In motion blur, however, unlike image blur caused by out-of-focus conditions and the like, the blur width varies greatly depending on the relative velocity between the camera and the subject, and since the direction in which blur occurs is anisotropic (blur occurs only the direction of the velocity vector of the motion between the camera and the subject), it is difficult to employ the prior art.
A blur function deconvolver technique using motion vector detection is disclosed in Patent Document 2. This technique requires a large amount of computation and for reasons of cost it is difficult to implement in practical circuitry.    Patent Document 1: Japanese Patent Application Publication No. 2002-16820    Patent Document 2: Japanese Patent No. 3251127